index.js

const fs = require('node:fs')
const { join } = require('node:path')
const basic = require('@antfu/eslint-config-basic')

const tsconfig = process.env.ESLINT_TSCONFIG || 'tsconfig.eslint.json'

module.exports = {
  extends: [
    '@antfu/eslint-config-basic',
    'plugin:import/typescript',
    'plugin:@typescript-eslint/recommended',
  ],
  settings: {
    'import/resolver': {
      node: { extensions: ['.js', '.jsx', '.mjs', '.ts', '.tsx', '.d.ts'] },
    },
  },
  overrides: basic.overrides.concat(
    !fs.existsSync(join(process.cwd(), tsconfig))
      ? []
      : [{
          parserOptions: {
            tsconfigRootDir: process.cwd(),
            project: [tsconfig],
          },
          parser: '@typescript-eslint/parser',
          excludedFiles: ['**/*.md/*.*'],
          files: ['*.ts', '*.tsx', '*.mts', '*.cts'],
          // https://github.com/typescript-eslint/typescript-eslint/blob/main/packages/eslint-plugin/src/configs/recommended-requiring-type-checking.ts
          rules: {
            'no-throw-literal': 'off',
            '@typescript-eslint/no-throw-literal': 'error',
            'no-implied-eval': 'off',
            '@typescript-eslint/no-implied-eval': 'error',
            'dot-notation': 'off',
            '@typescript-eslint/dot-notation': ['error', { allowKeywords: true }],
            '@typescript-eslint/no-floating-promises': 'error',
            '@typescript-eslint/no-misused-promises': 'error',
            '@typescript-eslint/await-thenable': 'error',
            '@typescript-eslint/no-for-in-array': 'error',
            '@typescript-eslint/no-unnecessary-type-assertion': 'error',
            '@typescript-eslint/no-unsafe-argument': 'error',
            '@typescript-eslint/no-unsafe-assignment': 'error',
            '@typescript-eslint/no-unsafe-call': 'error',
            '@typescript-eslint/no-unsafe-member-access': 'error',
            '@typescript-eslint/no-unsafe-return': 'error',
            'require-await': 'off',
            '@typescript-eslint/require-await': 'error',
            '@typescript-eslint/restrict-plus-operands': 'error',
            '@typescript-eslint/restrict-template-expressions': 'error',
            '@typescript-eslint/unbound-method': 'error',
          },
        }, {
          // https://github.com/jest-community/eslint-plugin-jest/blob/main/docs/rules/unbound-method.md
          files: ['**/__tests__/**/*.ts', '**/*.spec.ts', '**/*.test.ts'],
          plugins: ['jest'],
          rules: {
            // you should turn the original rule off *only* for test files
            '@typescript-eslint/unbound-method': 'off',
            'jest/unbound-method': 'error',
          },
        }],
  ),
  rules: {
    'import/named': 'off',

    // TS
    '@typescript-eslint/ban-ts-comment': ['error', { 'ts-ignore': 'allow-with-description' }],
    '@typescript-eslint/member-delimiter-style': ['error', { multiline: { delimiter: 'none' } }],
    '@typescript-eslint/type-annotation-spacing': ['error', {}],
    '@typescript-eslint/consistent-type-imports': ['error', { prefer: 'type-imports', disallowTypeAnnotations: false }],
    '@typescript-eslint/consistent-type-definitions': ['error', 'interface'],
    '@typescript-eslint/prefer-ts-expect-error': 'error',

    // Override JS
    'no-useless-constructor': 'off',
    'indent': 'off',
    '@typescript-eslint/indent': ['error', 2, {
      SwitchCase: 1,
      VariableDeclarator: 1,
      outerIIFEBody: 1,
      MemberExpression: 1,
      FunctionDeclaration: { parameters: 1, body: 1 },
      FunctionExpression: { parameters: 1, body: 1 },
      CallExpression: { arguments: 1 },
      ArrayExpression: 1,
      ObjectExpression: 1,
      ImportDeclaration: 1,
      flatTernaryExpressions: false,
      ignoreComments: false,
      ignoredNodes: [
        'TemplateLiteral *',
        'JSXElement',
        'JSXElement > *',
        'JSXAttribute',
        'JSXIdentifier',
        'JSXNamespacedName',
        'JSXMemberExpression',
        'JSXSpreadAttribute',
        'JSXExpressionContainer',
        'JSXOpeningElement',
        'JSXClosingElement',
        'JSXFragment',
        'JSXOpeningFragment',
        'JSXClosingFragment',
        'JSXText',
        'JSXEmptyExpression',
        'JSXSpreadChild',
        'TSTypeParameterInstantiation',
        'FunctionExpression > .params[decorators.length > 0]',
        'FunctionExpression > .params > :matches(Decorator, :not(:first-child))',
        'ClassBody.body > PropertyDefinition[decorators.length > 0] > .key',
      ],
      offsetTernaryExpressions: true,
    }],
    'no-redeclare': 'off',
    '@typescript-eslint/no-redeclare': 'error',
    'no-use-before-define': 'off',
    '@typescript-eslint/no-use-before-define': ['error', { functions: false, classes: false, variables: true }],
    'brace-style': 'off',
    '@typescript-eslint/brace-style': ['error', 'stroustrup', { allowSingleLine: true }],
    'comma-dangle': 'off',
    '@typescript-eslint/comma-dangle': ['error', 'always-multiline'],
    'object-curly-spacing': 'off',
    '@typescript-eslint/object-curly-spacing': ['error', 'always'],
    'semi': 'off',
    '@typescript-eslint/semi': ['error', 'never'],
    'quotes': 'off',
    '@typescript-eslint/quotes': ['error', 'single'],
    'space-before-blocks': 'off',
    '@typescript-eslint/space-before-blocks': ['error', 'always'],
    'space-before-function-paren': 'off',
    '@typescript-eslint/space-before-function-paren': [
      'error',
      {
        anonymous: 'always',
        named: 'never',
        asyncArrow: 'always',
      },
    ],
    'space-infix-ops': 'off',
    '@typescript-eslint/space-infix-ops': 'error',
    'keyword-spacing': 'off',
    '@typescript-eslint/keyword-spacing': ['error', { before: true, after: true }],
    'comma-spacing': 'off',
    '@typescript-eslint/comma-spacing': ['error', { before: false, after: true }],
    'no-extra-parens': 'off',
    '@typescript-eslint/no-extra-parens': ['error', 'functions'],
    'no-dupe-class-members': 'off',
    '@typescript-eslint/no-dupe-class-members': 'error',
    'no-loss-of-precision': 'off',
    '@typescript-eslint/no-loss-of-precision': 'error',
    'lines-between-class-members': 'off',
    '@typescript-eslint/lines-between-class-members': ['error', 'always', { exceptAfterSingleLine: true }],

    // antfu
    'antfu/generic-spacing': 'error',

    // off
    '@typescript-eslint/consistent-indexed-object-style': 'off',
    '@typescript-eslint/naming-convention': 'off',
    '@typescript-eslint/explicit-function-return-type': 'off',
    '@typescript-eslint/explicit-member-accessibility': 'off',
    '@typescript-eslint/no-explicit-any': 'off',
    '@typescript-eslint/parameter-properties': 'off',
    '@typescript-eslint/no-empty-interface': 'off',
    '@typescript-eslint/ban-ts-ignore': 'off',
    '@typescript-eslint/no-empty-function': 'off',
    '@typescript-eslint/no-non-null-assertion': 'off',
    '@typescript-eslint/explicit-module-boundary-types': 'off',
    '@typescript-eslint/ban-types': 'off',
    '@typescript-eslint/no-namespace': 'off',
    '@typescript-eslint/triple-slash-reference': 'off',
    // handled by unused-imports/no-unused-imports
    '@typescript-eslint/no-unused-vars': 'off',
  },
}